Year per Person 1980 2.33968 1981 2.61013 1982 2.61826 1983 3.42543 1984 3.62243 1985 3.76229 1986 3.83143 1987 4.3353 1988 4.72435 1989 4.75235 1990 4.65021 1991 5.31205 1992 4.34224 1993 4.20963 1994 4.29427 1995 4.27952 1996 4.00748 1997 3.95302 1998 3.82527 1999 3.0011 2000 2.86555 2001 2.62536 2002 2.45499 2003 1.9154 2004 1.75785 2005 1.63629 2006 1.31468 2007 1.16561 2008 0.96844 2009 0.87939 2010 0.91185 2011 0.86063 2012 0.82074 2013 0.77708 2014 0.74369 2015 0.68106 2016 0.5291